生物热物性全参数辨识技术及其切片实验研究

A Technique for Identifying the Total Parameters (TITP) of Biological Bodies and a Slicing Experimental Study

提出了一套可用于同时确定生物在体组织中随空间变化的导热率K、血液灌注率W_b和代谢热产率q_m以及导温系数α的新方法,从而克服了传统生物热物性测试技术中只能测量常物性的K、W_b和α而q_m难以利用Pennes方程测出的不足,为同时考察活体组织非均匀热参数的空间分布规律找到了一条可行途径,这是一种具有普遍意义性的方法.文中给出了一个针对大鼠头部组织的物性辨识算例,并采用切片实验考察了该方法的实际应用问题,发现采用表面力,热的办法测取材料热物性时,所得结果的精度受热渗透深度限制,并继而提出了采用空间加热措施以提高物性测试精度的设想.

A new technique for simultaneously identifying the space dependent thermal conductivity K , blood perf usion rate Wb , metabolic rate qm and thermal diffusivity a is proposed in this paper. The shortcomings of classical methods which can only measure constant K, Wb and a while qm can not be obtained through Pennes' equation is overcome, thus a possible and generalized approach for evaluating in vivo the space dependence of the nonhomogeneous thermal properties is obtained. An example for identifying the thermal properties inside a cat's brain under cooling is given and the practical application of this method is studied in a slicing experiment. It is found that, when surface heating is applied, the property measurement accuracy is confined to the thermal permeating depth, and a proposal to improve accuracy through spatial heating is suggested.